Submission #767335

#	Time	Username	Problem	Language	Result	Execution time	Memory
767335		sysia	The Kingdom of JOIOI (JOI17_joioi)	C++17	100 / 100	607 ms	70660 KiB

joioi

//Sylwia Sapkowska
#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
using namespace std;

void __print(int x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << "'" << x << "'";}
void __print(const char *x) {cerr << '"' << x << '"';}
void __print(const string &x) {cerr << '"' << x << '"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ", "; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef LOCAL
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif

#define int long long
typedef pair<int, int> T;
const int oo = 1e18, oo2 = 1e9+7, K = 30;
const int mod = 998244353;

void solve(){
    int n, m; cin >> n >> m;
    vector a(n+1, vector<int>(m+1));
    int mx = -oo, mn = oo;
    T A, B;
    for (int i = 1; i<=n; i++){
        for (int j = 1; j<=m; j++){
            cin >> a[i][j];
            if (a[i][j] > mx){
                mx = a[i][j];
                A = {i, j};
            }
            if (a[i][j] < mn){
                mn = a[i][j];
                B = {i, j};
            }
        }
    }
    if (mn == mx){
        cout << "0\n";
        return;
    }
    int ans = mx-mn;
    auto sortuj = [&](vector<int>L, vector<int>R){
        debug(L, R); //a[i] \in [L[i], R[i]]
        //1) increasing
        bool ok = 1;
        vector<int>tab(n+1);
        for (int i = 1; i<=n; i++){
            tab[i] = L[i];
            if (i > 1) tab[i] = max(tab[i], tab[i-1]);
            if (tab[i] > R[i] || tab[i] < L[i]){
                ok = 0;
                break;
            }
        }
        if (ok) return true;
        ok = 1;
        //2) decreasing
        for (int i = 1; i<=n; i++){
            tab[i] = R[i];
            if (i > 1) tab[i] = min(tab[i], tab[i-1]);
            if (tab[i] > R[i] || tab[i] < L[i]){
                ok = 0;
                break;
            }
        }
        return ok;
    };
    
    auto check = [&](int k){
        //max(A-mn, mx-B) = k;
        //A <= k + mn
        //B >= mx - k
        debug(k+mn, mx-k);
        //sprawdzic czy da sie przypisac
        //0) z lewa minimum
        //1) z lewa maksimum
        for (int rep = 0; rep < 2; rep++){
            vector<int>R(n+1, m), L(n+1, 0);
            bool ok = 1;
            for (int i = 1; i<=n; i++){
                for (int j = 1; j<=m; j++){
                    if ((!rep && a[i][j] > k + mn) || (rep && a[i][j] < mx - k)){
                        R[i] = j-1;
                        break;
                    }
                }
                for (int j = R[i]+1; j<=m; j++){
                    if (!rep) ok &= (a[i][j] >= mx-k);
                    else ok &= (a[i][j] <= k+mn);
                }
                for (int j = R[i]; j>=1; j--){
                    if ((!rep && a[i][j] < mx-k) || (rep && a[i][j] > k+mn)){
                        L[i] = j;
                        break;
                    }
                }
            }
            if (ok && sortuj(L, R)) return true;
        }
        return false;
    };

    //ans = max(mx-A, B-mn);
    int l = 1, r = oo;
    while (r >= l){
        int mid = (l+r)/2;
        if (check(mid)){
            ans = mid;
            r = mid-1;
        } else {
            l = mid+1;
        }
    }
    ans = min(ans, mx-mn);
    cout << ans << "\n";
}

int32_t main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int t = 1;
    //cin >> t;
    while (t--) solve();

    return 0;
}

• Subtask 1: 15 / 15
• Subtask 2: 45 / 45
• Subtask 3: 40 / 40